[1] D. Procine and W. Hirt, IEEE Communication Magazine 41, 66 (2003).

[2] Federal Communications Commission, Second Report and Order and Second Memorandum Opinion and Order, Dec. 2004: p. 04-285.

[3] X. Chen and S. Kiaei, in Proceedings of IEEE Int. Symp. Circuits Syst. I 597 (2002).

[4] Y. Fan, L. Shi, G. Liu, W. Wang, J. Zhu, F. Liu, and Y. Zhou, High Power Laser and Particle Beams (in Chinese)16, 501 (2004).

[5] F. Guo and Y. Zhuang, Acta Photon. Sin. (in Chinese) 35, 1345 (2006).

[6] Y. Zhao, D. Zhao, Y. Liu, and L. Huang, Chinese J. Lasers (in Chinese) 36, 92 (2009).

[7] T. Kawanishi, T. Sakamoto, and M. Izutsu. in Proceedings of IEEE Int. Topical Meeting Microw. Photon. (MWP'06) 14 (2006).

[8] Q. Wang and J. Yao, Electron. Lett. 42, 1304 (2006).

[9] Q. Wang, F. Zeng, S. Blais, and J. Yao, Opt. Lett. 31, 3083 (2006).

[10] C. Wang, F. Zeng, and J. Yao, IEEE Photon. Technol. Lett. 19, 137 (2007).

[11] I. S. Lin, J. D. McKinney, and A. M. Weiner, IEEE Microw. Wireless Compun. Lett. 15, 226 (2005).